Wire coil and method of making same



Aug.9,1932. HDE JONG 1,870,713

' WIRE COIL AND METHOD OF MAKING SAME Filed Feb. 12, 1950 INVENTORHENDRIK dc JONG I BY MW ATTORNEY 1 Patented Aug. 9, 1932 UNITED STATESPATENT OFFICE HENDRIX DE J'ONG, 0F EINDHOVEN, NETHERLANDS, ASSIGNOB TORADIO CORPORA- TIONOF AMERICA, A CORPORATION OF DELAWARE WIRE COIL ANDMETHOD OF MAKING-SAME Application filed February 12, 1930, SerialN0.-f42 7,720, and in the Netherlands February'22, 1929.

The present invention relates to the art of coil winding and moreparticularly is directed to electrical coils .wherein insulating stripsare inserted between adjacent layers.

It is known when winding wire coils to separate the layers of wirewindings by layers of a material suitable for that purpose, for example,paper. The latter layers may be applied by slipping elongated stripsbetween the layers of wire windings duringthe operation of winding thewire and winding them on :-the bobbin. The process iscarried out asfollows: when a layer of wire windings has been wound and the wire hasarrived at the flange ofthe bobbin, the strip is fed and slipped betweenthe wire-and the newly completed layer of wirewindings. Thus the stripis gripped by the wire and wound on the bobbin, whereupon the next layerof wire windings is wound on this coiled strip.

According to the method of the invention the strip before it is wound isprovided with at least one bevelled end, after which it is fed so thatthe sharp point of the bevelled end is adjacent the side where the stripon being wound on the bobbin is gripped by the wire. The advantage ofthis method consists in that the strip is pulled taut around the coil sothat practically no wrinkles can ensue.

When the strips are fed from a supply roller and at the same time outinto proper lengths, they may be severed so that the incisions formedare slanting with respect to the longitudinal axis of the strip sothatthe successive incisions zigzag. Thus it is possible to shift thepointed edge of the strip during the winding operation successivelytowards another flange side of the bobbin.

The coils thus wound have the advantage of being very compact and smallbecause the material of the strip is prevented from wrinkling.Transformer coils, for example, may be wound advantageously in thismanner.

In order to assist the winding of coils of small size, strips of unequallength may be wound between the wire windings in such a manner that thelarger the diameter of the layers,the longer are the strips.

The coilmade by the method of the invention is characterized in that thestrips between the wire windings are bevelled at least at one end.

The arrangement for carrying out the method (Of the invention maycomprise a cutting apparatus that separates the strips provided with abevelled end off the supply roller. In order to cause the incisions tozigzag a cutting mechanism is provided which between two successiveincisions is rocked about a surface which is at right angles to thediredtion in which the strip is moved.

The invention will be more clearly understood by reference drawing inwhich:

Figure 1 is a perspective view of a wire coil being wound in accordancewith the present invention; a

Figure 2 is another View thereof showing the bevelled insulation layerhaving the sharp edge at the other side of the coil;

Figure 3 illustrates an insulation strip having a single bevelled edgein accordance with the present invention;

Figure 4 illustrates a strip of insulation material of undeterminedlength which is cut in accordance with the present invention;

Figure 4a illustrates a single piece of insulation material having bothits edges 1: *velled; and,

Figures 5 and 6 illustrate details of the mechanisms adapted to cut theinsulation strips in accordance with the present invention.

Figure 1 is a perspective view of a wire coil 10 shown at the momentwhen a paper strip 13 is slipped between a completed layer of windings11 and 'the winding wire 12. The strip 13 is provided with a bevelledend 14 andis fed so that the sharp point 15 of this end is adjacent thatside of the bobbin where it can be gripped by the wire 12 and can bewound around the winding layer 11.

Figure 2 shows the same coil after a new layer of wire windings has beenwound over the paper strip 13. Thus, the wire winding is adjacent theright hand flange of the bobbin to the accompanying strips of unequallength are a manner that the larger the diameter of the and this timethe strip has a bevelled end such that the sharp point 15 is locatedadjacent the right hand flange. Therefore it follows that it isimportant that the strips should be fed so that the sharp points arrivesuccessively on the left and on the right flange.

Figure 3 shows a single strip having only one bevelled end.

Figure 4: shows a strip of undetermined length, the diagonal lines shownindicate the manner in which the strip must be cut in order that thesharp point of the strip is caused to be fed successively adjacent theleft hand and the right hand flange of the bobbin. As is clearly shownin Figure 4:

these incisions zig-and-zag. The arrangement adapted for this purpose isshown in Figures 5 and 6. It comprises a cutting mechanism 20, 21mounted on a shaft 23. The cutter 20 is Vertically slidable on the shaft23 by means of a key-guide, whereas the cutter 21 is fast thereon. Theshaft 23 is journalled in the bearing 24:; the rotary movement isensured by a crank 25 and a rod 26; the cutter 20 is moved up and downby a rod 27. It is clearly shown in Figure 6 in what manner thearrangement operates. The strip 13 is first severed in position A of thecutting mechanism and then in position B. This arrangement is highlyeffective as it permits of the strips being fed rapidly and properly onto the coils to be wound.

Claims:

1. A method of winding transformer coils composed of alternate layers ofwire windings and coiled insulation strips which comprises bevelling atleast one of the ends of each of the insulation strips before they arewound and feeding the strip so that the sharp point of the bevelled endis adjacent that side of the bobbin where the strip is gripped by the:Tlnding Wire.

2. A method as claimed in claim 1, in which the strips are fed and arecut at proper lengths from a supply and in which these strips aresevered so that the incisions formed are slanting with respect to thelongitudinal axis of the strip so that the successive incisions zigzag.

3. A method as claimed in claim 1, in which wound in such layers, thelonger are the strips.

4. A wire coil which comprises alternate layers of Wire windings andcoiled strips of a material adapted to effectively separate thesewindings, said strips being bevelled at least at one end.

5. A wire coil as claimed in claim 4:, in A which the strips thereof areof unequal length such that the larger the diameter of the layers,

the longer the strips.

HENDRIK DE JONG.

